Looking at a 165,000 mile LT1 I figure it about time to start building a "replacement" engine.

While I've been able to find pages and pages of discussions regarding rotating assembly, and even one thread discussion block filler, I was wondering if there was anything else that can/should be done for a high-performance block while it's naked and I have free reign with the grinder.

Here's my plan so far, I was hoping the experienced builders could pass on a few tips or add anything they feel would be benificial:

1. Tap and use threaded freeze plugs. I couldn't really find info on this, however I started a separate thread specificly for finding manufactures & kits.
2. Freeze plug retaining straps. Drill/tap retaining screw holes outside each freezeplug and use 1/4" aluminum straps to keep plugs in place and slow coolant loss, should I really mess up on assembly (I have a feeling these will be unnessesary with threaded plugs... but my own peace of mind makes the effort seem worth it really).
3. Smooth oil gallery & head drainage channels (80 grit then 40 grit)

4. clean the block, rinse

5. Hard Block bottom 1.5" or so. The car this engine is building built for is currently a dialy driver, although by the time it's installed I'll probably retire the bird to crusie-in/drag-strip duty.

6. Strip off exterior paint

Have the shop:
7. hot tank the block
8. a) drill/tap 4-bolt main caps
8. b) align bore the main bearing seats
8. c) bore the cylinders to 4.030 (sonic check perhaps?)
8. d) deck the block to 9.005" (Felpro gasket will give 0.040" quench)

9. clean the block, then paint with Por-15

What am I missing? anyone have some trick ideas to add while the block is naked?

 

I've always followed the writings of John Lingenfelter and Smokie Y.
Both have very good books

 

I have John's "how to build a high-perf Chevy Small block"... awesome book in my mind. I also have/like the "rebuilding a LT1/LT4" by Mike Mavrigian.

I'll dig up some Smokie books, they're on the list with David V's stuff as well. I've got plenty of chasis and suspension books, just trying to delv into engine design with my 383 project starting to take shape (slowly ).

you know what they say about measure twice, cut once.

 

1. Never seen a need for this

2. This too. If you're poping freeze plugs, you have a serious problem in your cooling system.

3. There are a lot of tricks for this. In a SBC I've seen the oil return holes tapped and plugged to force the returning oil to the back of the engine so it won't drop onto the crank. Valley screens should also be used to catch anything big (valve train stuff) from getting into the pan. Another trick is to paint the lifter valley so that the oil has a smoother surface to flow over. The majority of the lifter valley tricks are not needed on a street engine.

4. Always after all the machine work is done. Pressure wash the entire block. If you're still dry when it's done then it's not clean enough. Compressed air to blow dry everything.

5. Not really needed unless you're making a lot of HP.

6. Hot tanking does this very well. A painted block is easier to keep clean. Same as aluminum parts such as heads, intake, valve covers. Base aluminum gets dirty fast. A simple paint job with aluminum paint keeps them clean for a long time and easier to clean once they get dirty.

7. Cam bearings, freeze plugs etc need to be replaced after hot tanking.

8a. Not really needed. Just use a stud kit.
8b. Yes
8c. That's a typical overbore. You'll need the pistons before it gets bored for final fitting.
8d. Depends on what parts you use. You can't guess on how much needs to be decked until a mockup is done and piston depth is measured. This means assembling and disassembling the engine a few times before final assembly.

Missing?
New pistons other than factory replacements means everything should be balanced.
There's nothing in there about cam or head choice. Lots more parts and measurements involved with that.
If you're just building a shortblock for a replacement it might be a lot cheaper to just buy a replacement shortblock that has everything done.

The majority of the time all the little "tricks" you can do to a block are not really needed and are really not needed on a street engine.

 

Thanks for the feedback. The concern about freeze plugs is more from a corrosion concern than anything else (and yes, to be fair some brass freeze plugs would do just as well in this issue).

The straps seem to be a circle-track mod that others (like Super Chevy editors) have recommended, although this is all stuff I'm gathering info on and am trying to wade through. Solid brass plugs with heavy thread engagement also shouldn't hurt block integrity at all... although I doubt it helps any substantial amount either. More for peace of mind really... I'd rather see a trickle of fluid behind the car, than a gusher of fluid wetting the track.

The block isn't a stock replacement, guess I should have clarified. While the current plan is for some LT1 castings getting worked over to ~280cfm, my target is ~500 fwhp NA. I know that seems a bit ambitious for N/A, but it's a goal I think is attainable with the right choice of parts. I'd like to see 420 to the wheels when this is done. The build up will consist of forged 6"rods and pistons, with an emphasis on small bob-weight (within reason). 500HP circle-track rods/pistons should be fine for daily driving with the same.

I've recently given thought to targeting ~600hp with Brodix 18x heads since Weisco pistons are available with valve reliefs that handle 18 and 23* valve reliefs, although the new Trick Flow heads with thick decks and larger runners also have their advantages. No matter what top-end design I plan on running initially, I'd like to keep my options opened. Compromising bob-weight for durability (for future hp gains) is kind of the issue I have right now. Most of the stuff I listed above seem to have little down-side, although the current configuration may not see a benefit either.



Obviously the block won't head to the shop until a rotating assembly is in my hands. As I said, this was more focused on the block itself (oil passages, coolant jackets, structural, etc...) the rotating assembly and bearing selection is a separate consideration I'm looking at (outside of clearance the block once I have the rotating assembly in hand).

Thanks for the suggestion on the aluminum heads... I dig the gleam of polished aluminum, but what a PITA to keep clean. I'm assuming there's a specific paint composition for "aluminum paint"?

I guess I could use some Por-15 like I had planned for the block (or Gyptal like the oil passages).... but I didn't want to worry about heat. Is it really that common to paint aluminum heads?

 

skip the strapping of the freeze plugs and have the machine shop install the freeze plugs for you it only 15.00 and they wont come out.If you use brass they will outlast the engine .

 

Yeah, Steve isn't understanding that freeze plugs don't come out in a 500-600hp engine. I've driven in dozens of sets, and not one has ever come out. Generally machine shops put them in with 3M weatherstripping adhesive.

As for your goals, it sounds like what you are considering is a lot more simple than you think. You need long tube headers, decent exhaust, and heads/cam from Phil (skarodoom) and you are there with tuning. Why spend ten times what you need to meet your goal?

 

I know this is ****, but if I have the time I like to grind all the sharp edges off, on the out side of the block.
Can't tell you how many times I've cut my hand because of some sharp slag or edge.

 

ok.. I understand that they typically don't come out in any engine (regardless of power level). The point is that "IF" I have the time, and "IF" I can get them in Brass, I'll feel better about the engine I'm building... even if it sounds like unnessesary effort to some.

This engine build is not about hitting the bare minimum on a budget, its about building an engine I'm confident about and yes, a little learning in the process.

The exhaust is taken care of (AS&M single-cat + 3" cat-back), heads will be from a local shop whose shown flow and HP numbers as nice as anything we've seen from the "head porter of the month". And the hp

I personally don't see how some threaded plugs, a little gyptal, and maybe some Por-15 will make my engine "ten times what [I] need to spend". I understand that a forged crank is probably not nessesary, and that billet rods are pointless, but I AM looking for small things that can help... even in a small way. Picking a piston that has allowances for 18* heads is an example. Even if it doesn't become nessesary, its nice to know it's there if I need it.

 

Just got next month "Hot Rod" and "Car Craft". In the new parts pages of one of them, there is a manufacturer that is selling the screw in plugs and the tap for the threads. Looks like a good deal.